Method for the operating control of a clothes washing machine and clothes washing machine

ABSTRACT

The method of the invention encompasses the stages of: rotating the basket in a weighing rotation determined by a microprocessor, of a top-loading machine, already containing the load of clothes to be washed; producing signals for a load sensing device, assembled on a suspension rod of a containment drum that holds the basket, of the maximum and minimum loads to which such suspension rod is subject during each spin of the basket, processing the above-mentioned signals in order to define the average load applied to the suspension rods and with this information, the weight of the load of clothes; and determine, through the microprocessor and as a function of the weight of the load of clothes, the weight of the load of water fed into the containment drum. The method in question also allows control over the various operating functions of the machine, through monitoring the load applied to the above-mentioned suspension rod.

FIELD OF THE INVENTION

This invention consists of a method for the operating control of aclothes washing machine, having determined the weight of the load fedinto the above-mentioned machine. More specifically, this inventionaddresses a method for the operating control of such machines and thatit encompasses the determination of the weight of the load of clothesand that of a corresponding load of water in a clothes washing machineof the top-loading type, in which a containment drum with a rotatingbasket inside it, is suspended in a casing of the machine by suspensionrods.

The invention also refers to a top-loading clothes washing machine withautomatic operation, fitted with devices that can determine the weightof the load of clothes and thus the amount of water to be let in for thewashing operation, in addition to, controlling the other operatingfunctions of the machine.

BACKGROUND OF THE INVENTION

One of the questions that must be resolved in the operation of a clotheswashing machine is that of determining the weight of the load of clothesput into the basket, in order to determine the load or the amount ofwater to be fed into the containment drum suspended inside the casing.Information on the weight of the load of clothes may be sent to acontrol device, such as a microprocessor in the actual washing machine,programmed to operate it and performing several functions.

The control of various operating functions of the clothes washingmachine, once the load of clothes has been determined by the machineitself, allows it to operate, with no need for any intervention by theuser, in the manner most appropriate to each amount of clothes put intothe basket, saving water and electricity, reducing the time needed forwashing and spin-drying each load of clothes while also permitting areduction in the vibrations, particularly while the basket is spinningduring the spin-drying phase.

Several arrays were offered by the previous technique, in order todetermine the weight of the load of clothes put into the basket of theclothes washing machine.

One of these arrays is described in Brazilian Patent application MU8400211-5, consisting of strain gauge type deformation sensors alignedwith the suspension rods of the water containment drum in the casing ofthe machine. The strain gage is a well-known resistance-measuring devicewhose resistance values vary, depending on the strains to which it issubjected. The information on weight acquired by the many load cells isconverted into an analog or digital electrical signal that is processedby an electronic module, such as a microprocessor.

The a load sensing device, such as strain gage, on each suspension rodallows the weight of the load of clothes put into the basket to beobtained with the machine non-operative, regardless of the distributionof the load of clothes, meaning the level of imbalance of the basket andthe load of clothes together.

However, a disadvantage of this previous solution is its relatively highcost, requiring four load sensing devices.

An alternative structure with lower costs uses a load sensing devicethat may consist, for example, of a single strain gage affixed to acalibrated metal body that is assembled on of the suspension rods, beingsubject to the loads applied thereto. This array does not result in ahigh-precision transducer, being able to detect the weight of the loadwith a resolution (number of increments) that is sufficient for use inonly some applications.

SUMMARY OF THE INVENTION

Prompted by the inconveniences mentioned above related to the systemsand methods currently known for determining the weight of the load in aclothes washing machine, an objective of this invention is to provide amethod for the operating control of such machines, encompassing theautomatic determination of the weight of the load of clothes put intothe basket of a clothes washing machine of the top-loading type, thatcan be implemented at a relatively low cost, using only one load sensingdevice mounted on the suspension rods of a containment drum of themachine and providing accurate and reliable results, regardless of thelevel of imbalance that the load of clothes produces in the rotatingbasket, when spinning round inside the containment drum.

An additional objective of this invention is to provide a method, asmentioned above, that also allows the definition, as a function ofdetermining the weight of the load of clothes put into the machine, theamount of water to be fed into the containment drum and also the amountof water removed during the spin-drying phase, thus resulting in awashing operation that consumes less time, electricity and water.

Another objective of the invention is to provide a clothes washingmachine of the type presented above that operates automatically,determining and controlling the amount of water fed into the containmentdrum, for its operation and washing functions, performing andcontrolling several other functions of the machine.

The method addressed by this invention is applied to a clothes washingmachine of the top-loading type and that encompasses: a casing; acontainment drum suspended inside the casing and sized to receive andcontain the load of water—several suspension rods connected underneathto the containment drum and on top to the casing; a basket, assembledinside the containment drum that is spun around its vertical geometricaxis by a motor unit carried by the containment drum, during aspin-drying phase of the machine, and sized to hold the load of clothesto be washed; and a microprocessor that activates various operatingfunctions of the machine.

According to an initial aspect of the invention, the method in questionencompasses the stages of: placing the load of clothes inside the basketof the machine; switching on the motor unit in order to switch thebasket into a weighing rotation that is pre-determined by themicroprocessor; through a load sensing device mounted on the suspensionrods, producing signals representing the maximum and minimum loads towhich the above-mentioned suspension rod is subject during each spin,charging the load sensing device in the above-mentioned weighingrotation of the basket already containing the load of clothes:

-   -   receiving and processing such signals in the microprocessor        during a certain pre-set period of time, in order to define the        average load applied to the above-mentioned suspension rod that        sets the load sensing device, considering this value for the        average load as representing that applied to each of the        suspension rods and determining, on the basis of the average        total load on the suspension rods, the weight of the load of        clothes placed in the basket; and    -   through the microprocessor and as a function of the weight of        the load of clothes already determined, determine the weight of        the load of water to be fed into the containment drum. In        addition to allowing fast and automatic automation of the weight        of the load of clothes and the weight of the load of water to be        fed into the machine, the method in question also allows the        microprocessor to send an instruction switch on the control        valve, with the basket motionless or turning in the weighing        rotation, fitted with a water feed pipe, facing it in the open        position, having determined the weight of the load of water to        be fed into the containment drum and in a closed position, at        rest, turning it off when the load of water fed into the        containment drum reaches the weight determined by the        microprocessor, as a function of the weight of the load of        clothes that has already been determined.

Other aspects of the method addressed by the invention are describedbelow in the course of this Report. The invention also encompasses aclosed washing machine as defined above, with one of its suspension rodsfitted with a load sensing device that is operationally connected to themicroprocessor in order to supply it with signals representing themaximum and minimum loads applied to the above-mentioned suspension rodwhile the basket is turning in a weighing rotation and alreadycontaining the load of clothes to be washed, with this microprocessorbeing designed to process these signals as a function of the definitionof the average load applied to such suspension rod that sets the loadsensing device and the number of suspension rods, and determine thecorresponding weight of the load of water fed into the containment drum.Other characteristics of the construction and operations of the machinein question are described below, in the detailed description of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

Other purposes and advantages of this invention will become clearthrough referring to the description presented below and the appendeddrawings, which are presented as an example of a possiblematerialization of the invention in which:

FIG. 1 is a front-view diagram of a typical clothes washing machine ofthe top-loading type;

FIG. 2 is a view of the plan of a load sensing device linking twoportions of a suspension rod to the drum and defining a calibrated bodyto which a strain gage is affixed;

FIG. 3 is a cross-section of the load sensing device, with this crosssection following the line A-A shown in FIG. 2;

FIG. 4 is a graph presenting the maximum and minimum load values appliedto the suspension rod which charges the load sensing device on eachcomplete spin of the basket when in a weighing rotation containing anunbalanced load of clothes; and

FIG. 5 presents a graph illustrating presenting a decreasing curve inthe variation exemplifying the weight of the total load (clothes andwater) during the spin-drying phase performed by the washing machine.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows the conventional clothes washing machine 10 of thetop-loading type, fitted with a casing 12, normally metal. The casing 12has a supporting foot 14 on each on each of its corners to support it onthe ground. The machine 10 includes a control panel 20, generallyassembled on the casing 12 and fitted with different switches, notdescribed here as they do not constitute part of this invention, throughwhich the user may select the various functions of the machine.

The machine in question encompasses also encompasses microprocessor 30,generally fitted inside the control panel 20, that is schematicallyillustrated in FIG. 1, with the above-mentioned microprocessor 30 builtin a manner that allows it to be programmed properly in order to controlthe operation of the various components and the respective functions ofthe machine, as well be described in the course of this Report. Acontainment drum 40 is suspended inside the casing 12, sized to receiveand hold the load of water to be fed into the machine during a washingoperation.

Inside the containment drum 40 a basket 50 is assembled, generally butnot necessarily perforated, that may be rotated by a motor unit 60around its vertical geometric axis, during a spin-drying phase of themachine 10 and that is also sized to hold the load of clothes to bewashed by the machine 10.

The containment drum 40 is suspended inside the casing 12 by severalsuspension rods 70, which are connected underneath to the containmentdrum 40 and above to the casing 12, as schematically illustrated in FIG.1, and as is well-known in the technique. Generally, four suspensionrods 70 are provided, equally spaced among themselves at around 90°around the containment drum 40, in the gap between it and the casing 12.

The motor unit 60 is generally assembled on the containment drum 40,consisting of a motor 61 and a switching mechanism 62, of adequateconstruction, generally of the belt and pulley type, operationallyconnected to the basket 50 in order to rotate it during the variousoperating phases of the machine 10.

According to a first aspect of the invention, one of the above-mentionedsuspension rods 70 carries a load sensing device 80 operationallyconnected to the microprocessor in order to send signals to the latterrepresenting the maximum and minimum loads applied to such suspensionrod 70, with the basket 50 being stationary or turning in a weighingrotation, generally below the spin-drying rotation of the basket andalready containing the load of clothes to be washed. The microprocessoris designed and built to process these signals received from the loadsensing device 80 on each complete spin of the basket 50, as a functionof the definition of the average load applied to the above-mentionedsuspension rod 70 and the number of rods 71, thus determining acorresponding weight for the load of water fed into the containment drum40.

As shown in FIG. 1, the machine 10 also encompasses a water feed pipe15, generally connected to the pressurized water network and fitted witha control valve 16, of the remote switching type, generally an electricvalve operationally connected to the microprocessor whereby itsactivation is controlled by the above-mentioned microprocessor 30.

Also as set forth in the configuration illustrated in FIGS. 2 and 3, theload sensing device 80 is assembled on only one of the suspension rods70 and consists of a calibrated body 81, constructed from anyappropriate material, such as steel, for example, and that may take theshape of a connector ring 82 that includes grommets 82 a, 82 b, facingand at the ends, with one above and the other below. In the constructionexample as illustrated, the above-mentioned suspension rod 70 is dividedat an intermediate point along its length, into two portions of rod 71,72, whose adjacent tips are each hooked in a respective grommet 82 a, 82b of the connector ring 82 of the calibrated body 81.

The load sensing device 80 also encompasses a strain gage 83 mounted onthe calibrated body 81, in order to sense the distortions thereof, whenthe loads are applied to the respective suspension rod 70, meaning thestrains imposed thereon by the weight of the containment drum 40, of thebasket 50, of the load of clothes already placed in the basket 50, theload of water fed into the containment drum 40 and also the strainsresulting from the spinning movement of the basket 50, alreadycontaining the load of clothes, in a weighing rotation controlled by themicroprocessor 30, as described in greater detail below.

As illustrated in FIG. 3, the strain gage 83 may be defined as a straingage to be affixed to the calibrated body 81, for example, on one of theinner edges of the connector ring 82, also being fitted with a pair ofoutlet wires 83 a. This must be defined by any sensor that can detectthe level of strain to which the calibrated body 81 is subject whenapplying the method in question. When using a strain gage, constructionmay be conventional, with resistance that varies according to thestressed applied to the connector ring 82, being measured and processedby the microprocessor 30. The electronic circuit connecting the loadsensing device 80 to the microprocessor may be handled in differentways, with one of them described here in the Application for BrazilianPatent PI 0602958-2 submitted by this same applicant, and that must beincluded here by reference.

With the construction defined above, it is possible to determine theweight of the load of clothes placed in the basket 50 of the machine 10,thus initially providing the energization of the motor unit 60 throughactivation of the command panel 20 to start up the operation of themachine, so that it can switch the basket 50 into a weighing rotationthat is pre-determined by the microprocessor 30 and that is generallysignificantly below the rated spin rate program for the spin-dryingphase of this type of automatic machine.

As from the time that the basket 50 begins to spin in the weighingrotation, already containing the load of clothes to be washed, thenatural imbalance of the load of clothes inside the basket will ensurethat, with each complete spin thereof, the load sensor 80 can detect thevalues of the maximum and minimum loads applied to the suspension rod 70that carries the above-mentioned load sensor device 80, with suchsignals representing the maximum and minimum loads being sent to themicroprocessor that processes these signals for a certain pre-set lengthof time or a certain number of complete spins of the basket 50, in orderto define the average load applied to the above-mentioned suspension rod70 and detected by the load sensor device 80, taking this average loadvalue as being the load applied to each of the other suspension rods 70.Having determined the average load applied to each suspension rod 70.Considering the number of suspension rods 70, the microprocessor 30determines the weight of the load of clothes placed in the basket 50.Having determined the weight of the load of clothes placed in the basket50, the microprocessor determines through adequate algorithms, theweight of the load of water to be pumped into the containment drum 40,in order to perform an adequate washing operation with the load ofclothes placed by the user inside the machine. This solution allows thewater fed into the machine to be measured in an accurate and automaticmanner, for each load of clothes placed in the perforated basket 50,saving water and electricity.

Another operating characteristic of the solution proposed hereinconsists of the manner in which the inflow of the load of water may becontrolled into the containment drum 40, in an adequate manner. Althoughbeing able to use systems that are well-known in the technique and thatmake use of pressure stats to measure the water column allowed insidethe containment drum 40 and thus established one or more different waterlevels inside the machine, the solution in question allows the elementspresented above to be used in order to not only control the inflow offlow into the machine, but also to ascertain whether this inflow istaking place correctly and, if not, issue an instruction command for themicroprocessor 30, to interrupt the washing operation, or to produce avisual or sound alarm, or both, in order to alert the user to theoccurrence of some problem related to the inflow of water, such as faultin the water inflow control valve, for example, blocked piping, inflowtap improperly closed or any other problem that affects the expectedinflow of the load of water into the containment drum 40.

According to one way of realizing the invention, having determined theweight of the load of clothes placed in the basket 50 and the weight ofthe load of water to be fed into the containment drum 40, the rotationof the basket 50 is interrupted, being immobilized through aninstruction sent by the microprocessor 30, when then sends aninstruction to automatically switching the control valve into an openposition, releasing the inflow of water into the containment drum. Asthe load of water does not cause any imbalance as it flows into thecontainment drum 40, the increase in the weight or the load detected bythe load sensing device 80 fitted to the suspension rods 70 correspondsto one quarter of the load of water effectively pumped in, allowing themicroprocessor to detect this through the signals received from the loadsensing device 80, processing the rising variation in the load until theprocessed value reach that representing the load of water fed into thecontainment drum 40.

Should the microprocessor detect an increase in the weight of the loadof water flowing in through control valve 16 in the open position belowa pre-set value per time unit, the microprocessor will send an operatingcommand, interrupting the automatic operation of the machine and/oremitting visual and/or sound alarm signals alerting the user.

It must also be understood that the operation of the control valve 16for starting and ending the inflow of the load of water into thecontainment drum 40 may be performed with the basket still in theweighing rotation, although this variant of the method in questionresults in electricity consumption corresponding to that required tomaintain the spin of the basket 50 in the weighing rotation, while thewater is flowing into the machine. In this variant of the method, thebasket 50 continues to turn in the weighing rotation after opening thecontrol valve 16, whereby the load sensing device 80 continues to sendsignals to the microprocessor 30, representing the maximum and minimumloads applied to the respective support rod 70 on each complete spin ofthe basket 30, allowing the microprocessor detect and process theincreasing variation in the range of the above-mentioned maximum andminimum loads, concluding on the variation in the above-mentioned range,until the maximum and minimum load values are reached representing thetotal load of water to be allowed into the containment drum 40. Shouldthe microprocessor ascertain that the increase of the weight of the loadof water allowed to flow into the containment drum 40 during the periodwhen the control valve 16 is open, still with the basket 50 turning inthe weighing rotation, below a pre-set value per time unit, themicroprocessor will send an operating command instruction in order tohalt the machine and/or allow alarm signals to alert the user.

The graph presented in FIG. 4 illustrates the maximum and minimum valuesof the loads applied to the suspension rod 70 that sets the load sensingdevice 80, with the range of variation in the load on each rotation ofthe basket 50, already containing the load of clothes with a certainimbalance, is illustrated here merely as an example, as the range ofloads applied to the above-mentioned suspension rod 70 will evidentlydepend on the level of imbalance of the load of clothes placed in thebasket 50, necessarily noting that the weighing rotation applied to thebasket 50 is pre-determined by the design of the machine. Anotherimportant aspect of this invention derives from the fact that thesolution proposed herein also allows control of the time and speed ofthe rotation of the basket 50 during the spin-drying phase of the loadof clothes already washed, from which the water used during the earlierphases must be expelled with the desired intensity. In the solutionsthat are currently known, the spin drying time is calculated as a valuethat is generally fixed and sufficient to produce an adequate extractionof water from the load of clothes, considering the load of clothes to beequal or close to the maximum value permitted by the design of themachine 10.

In the case of this invention, the microprocessor 30 can accompany thedecreasing variation in the average load applied to suspension rod 70that sets the load sensing device 80, on each rotation of the basket 50,during the spin-drying phase of the load of clothes that has alreadybeen washed. Thus, when the decreasing variation in the average loadapplied to the above-mentioned suspension rod by time unit, is below apre-set value, the microprocessor instructs the motor unit 60 to switchoff in order to complete the spin-drying phase and the rotation of thebasket, interrupting electricity consumption and avoiding unnecessarycrumpling of the clothes, having extracted from the load of clothesalmost all possible water, considering the spin speed-drying assigned tothe basket 50 by the rated design.

As shown through the graph presented in FIG. 5, the microprocessor 30monitors the decreasing variation in the maximum and minimum loadsapplied to the above-mentioned suspension rod 70 that sets the loadsensing device 80, detecting the initial spin-drying phases,conventionally applied, in order to allow some settling of the clothesin the basket and also during the subsequent high, medium and low waterextraction phases, illustrative in the curve of the above-mentionedgraph.

When the decreasing variation in the above-mentioned average load or therange of variation in the loads applied to the above-mentionedsuspension rod on each rotation of the basket 50, if less than aspecific value pre-established as function of a time unit, there is notechnical reason for the machine to continue operating, with the motorunit 60 remaining switched on to spin the basket 50. The spin-drying maythus be interrupted at the most appropriate time in terms of the waterextraction level from the load of clothes, thus avoiding unnecessaryelectricity consumption and operating time for the machine. Theinvention also allows a stage to be included that checks the decreasingvariation in the average load applied to the suspension rod 70 throughthe microprocessor 30, that sets the load sensing device 80 on eachrotation of the basket 50, during the spin-drying phase of the load ofclothes that has already been washed and sends an operating commandinstruction, should the weight of the load of water drop or should thevariation fall below a preset value per time unit. The above-mentionedoperating command instruction may be designed to perform one or both ofthe functions defined by the interruption of the washing operation or bysetting off a sound alarm alerting the user.

Still considering the possibility of the spin-drying phase beingperformed with a load of clothes arranged in a manner that may result insevere imbalance during the rotation of the basket 50, the inventionalso makes provision for the possibility of adjusting the rotation speedof the basket 50 during the above-mentioned spin-drying phase, throughan instruction sent by the microprocessor 30 to the motor unit 60, inorder to keep the maximum load detected by the sensing device 80 on eachrotation of the basket 50 below the pre-set ceiling value, below thepreset ceiling value, thus protecting the structure of the machineagainst excessive vibration that occurs when the spin-drying phase takesplace with severe imbalance.

In addition to the solution proposed hereby that allows automaticcontrol of the rotation speed of the basket 50 during the spin-dryingphase, in order to adapt it to the level of imbalance of the load ofclothes and thus avoid undesirable levels of vibration in the machine,it must also be understood that it is possible for the microprocessor 30to adjust the rotating speed of the basket during the spin-drying phase,through processing the maximum and minimum load signals received fromthe load sensing device 80, keep it at least a slower rotation level asselected by the user, in order to leave the load of clothes lesscrumpled, so that they may be ironed more easily. Thus, the user mayadjust the rotating speed of the basket 50 during the spin-drying phase,in order to endow the load of clothes being spin-dried with a desiredlevel of compacting or crumpling.

In the solution proposed hereby, through detecting the times of eachspin cycle of the basket 50 among the five maximum and minimum loadoptions detected by the load sensing device 80, it is possible todetermine the rotation speed of the basket 50. Thus, the microprocessormay be programmed to process the load range signals detected by the loadsensing device 80 and instruct the motor unit 60 to switch off forsufficiently brief periods of time and in an appropriate sequence asrequired to keep the basket 50 rotating at speeds that do not result ina maximum load higher than the pre-set ceiling value as mentioned above,or that allow the release of the load of clothes already washed and thatmay be ironed more easily. Although one form of the above-mentionedmanner of realizing this invention is presented here, it must beunderstood that various obvious modifications may be introduced otherthan those understood in the technique, without moving away from theinventive concept defined in the Claims accompanying this Report.

1. Method for the operating control of a clothes washing machine of thetop-loading type and that comprises: a casing; a containment drumsuspended inside the casing and sized to receive and hold the load ofwater; a plurality of suspension rods connected underneath to thecontainment drum and above to the casing; a basket, assembled inside thecontainment drum, so that it is rotated by the motor unit, on itsvertical axis, during a spin-drying phase of the machine, and sized tohold a load of clothes to be washed; and a microprocessor to activatethe various operating functions of the machine, said method comprising:placing a load of clothes in the basket of the machine; energizing themotor unit in order to drive on the rotation the basket at a weighingrotation pre-determined by the microprocessor; producing signals bymeans of a load sensing device mounted on one of the suspension rods,wherein the signals represent the maximum and minimum loads to whichsuch suspension rod is subject during each spin, in the above-mentionedweighing rotation of the basket already containing the load of clothes;receiving and processing such signals by the microprocessor during acertain pre-set period of time, in order to define the average loadapplied to the above-mentioned suspension rod and detected by the loadsensing device, considering this average load value as representing thatapplied to each of the suspension rods and determining from the averagetotal load on the suspension rods, the weight of the load of clothesplaced in the basket; and determining by means of the microprocessor andas a function of the weight of the load of clothes already determined,the weight of the load of water to be fed into the containment drum. 2.Method, as set forth in claim 1 whereby the machine also comprises awater feed pipe fitted with a control valve that is remotely activatedand operational connected to the microprocessor, with the methodcomprising: interrupting the activation of the basket in the weighingrotation and immobilizing it, when instructed to do so by themicroprocessor; switch the control valve into an open position, wheninstructed to do so by the microprocessor and after determining theweight of the load of water to be pumped in and/or the containment drum;switch the control valve into a closed position at rest, when instructedto do so by the microprocessor and when the load of water fed into thecontainment drum reaches the weight determined by the microprocessor asa function of the pre-determined weight of the load of clothes. 3.Method as set forth in claim 2, which comprises the stage checkingthrough the microprocessor the occurrence of an increase of the weightof the load of water being pumped into the containment drum, during thetime that the control valve is open; and producing an operating commandinstruction should the weight of the load of water continue to increasebelow the a pre-set value per time unit.
 4. Method, as set forth inclaim 1 of remote switching, and operationally connected to themicroprocessor, as this machine also includes a water feed pipe fittedwith a control valve, with the method comprising: keeping the basketturning in the predetermined weighing rotation; switching the controlvalve into an open position, as instructed by the microprocessor, afterdetermining the weight of the load of water to be fed into thecontainment drum. switching the control valve into a closed position,turning it off, as instructed by the microprocessor when the load ofwater fed into the containment drum reaches the weight determined by themicroprocessor as a function of the weight of the load of clothesalready determined.
 5. Method, as set forth in claim 4, which furthercomprises ascertaining through the microprocessor the occurrence of anincrease of the weight of the load of water being pumped into thecontainment drum, during period when the control valve is open and withthe basket still turning in the weighing rotation, producing anoperating command instruction should the weight of the load of watercontinue to increase below a pre-set value per time unit.
 6. Method, asset forth in either claim 3, wherein the operating command instructionproduces the interruption of the washing operation.
 7. Method, as setforth in either claim 3, wherein the operating command instructionincludes setting off a visual and/or sound alarm.
 8. Method, as setforth in claim 1, which ascertaining through the microprocessor, thedecreasing variation in the average load applied to the suspension rodthat sets another load sensing device on each rotation of the basket,during the spin-drying phase of the load of clothes already washed;switching off the motor unit and finalizing the spin-drying phase andthe rotation of the basket when this decreasing variation of the averageload applied to the above-mentioned suspension rod that sets the loadsensing device, per time unit, falls below a pre-set value.
 9. Method,as set forth in claim 1, which comprises adjusting the rotating speed ofthe basket during the spin-drying phase as instructed by themicroprocessor to the motor unit, in order to maintain the maximum loaddetected by the load sensing device on each rotation of the basket belowthe pre-set ceiling value.
 10. Method, as set forth in claim 1, whichcomprises adjusting the rotating speed of the basket during thespin-drying phase, keeping it, as instructed by the microprocessor andat one lower level at least as selected by the user, in order to ensurea desired level of compacting on load of clothes being spin-dried. 11.Method, as set forth in claim 1, which comprises ascertaining, throughthe microprocessor, the decreasing variation in the average load appliedto suspension rod that sets the load sensing device on each spin of the,during the spin-drying phase of the load of clothes already washed; andproduces an operating command instruction should the weight of the loadof water drop less than the pre-set value per time unit.
 12. Method, asset forth in claim 11, which comprises operating command instructionperforming at least one of the functions defined by interrupting thewashing operation and setting off a visual and/or sound alarm. 13.Method, as set forth in claim 1, wherein the load sensing device is astrain gage mounted on a calibrated metal body linking the two portionsof the above-mentioned suspension rod.
 14. Clothes washing machine ofthe top-loading type and that comprise: a casing; a containment drumsuspended inside the casing and sized to receive and hold the load ofwater; a plurality of suspension rods connected underneath to thecontainment drum and above to the casing; a basket, assembled inside thecontainment drum, so that it is rotated by the motor unit and on itsvertical axis, during a spin-drying phase of the machine and sized tohold the load of clothes to be washed; and a microprocessor thatactivates the various operating functions of the machine, wherein thesesuspension rods carries a load sensing device operationally associatedto the microprocessor in order to supply signals to the latterrepresenting the maximum and minimum loads applied to such suspensionrod by the spin of the basket in a weighing rotation and alreadycontaining the load of clothes to be washed, said microprocessor beingdesigned to process such signals, as a function of the definition of theaverage load applied to the above-mentioned suspension rod and thenumber of suspension rods, and determining a corresponding weight of theload of water to be fed into the containment drum.
 15. Machine, as setforth in claim 14, further comprising a water feed pipe fitted with acontrol valve that is remotely switched and operationally connected tothe microprocessor, with this machine being characterized by the factthat the microprocessor switches the control valve into an open positionafter determining the weight of the load of water, and into closedposition at rest when the load of water in the containment drum reachesthe weight determined as a function of the weight of the load ofclothes.
 16. Machine, as set forth in claim 15, wherein themicroprocessor produces an operating command instruction when theincrease of the weight of the load of water, with the control valve inthe open position, falls below a pre-set value per time unit. 17.Machine, as set forth in claim 16, wherein the operating commandinstruction performs at least one of the functions defined byinterrupting the washing operation and setting off a visual and/or soundalarm.
 18. Machine, as set forth in claim 14, wherein the microprocessoris designed to switch off the motor unit and finalize the spin-dryingphase when the decreasing variation in the average load applied to theabove-mentioned support rod that sets the load sensing device, per timeunit, falls below a pre-set value.
 19. Machine, as set forth in claim14, wherein the microprocessor adjusts the rotating speed of the basketduring the spin-drying phase, through controlling the switching on ofthe motor unit, in order to maintain the maximum load on theabove-mentioned suspension rod that sets the load sensing device, oneach rotation of the basket below the pre-set ceiling value. 20.Machine, as set forth in claim 14, wherein the microprocessor adjuststhe rotating speed of the basket, during the spin-drying phase, throughcontrolling the switching on of the motor unit and at one lower level atleast as selected by the user, in order to ensure a desired level ofcompacting on load of clothes being spin-dried.
 21. Machine, as setforth in claim 14, wherein the microprocessor produces an operatingcommand instruction when, during the spin-drying phase, the decreasingvariation in the average load applied to the above-mentioned support rodthat sets the load sensing device, per time unit, falls below a pre-setvalue.
 22. Machine, as set forth in claim 21, wherein the operatingcommand instruction performs at least one of the functions defined bythe interruption of the washing operation and setting off a visualand/or sound alarm.